POTENTIAL APPLICATION AND DESIGN OF SUPERCRITICAL CO2 TURBOEXPANDER TO IMPROVE THE ECONOMY OF EAST NATUNA GIANT GAS FIELD

• Main Author: Pala'biran, Merandy
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/69803
• Institution: Institut Teknologi Bandung

The East Natuna Field at the South China Sea (SCS) has an estimated original gas in place of 222 trillion cubic feet (TCF) with 71% CO2 content. Because of his very high CO2 content, it causes a tremendous challenge to develop a project for this field that was discovered in 1974. A huge, costly CO2 removal plant has to be constructed that makes the project very difficult to be economical. For this reason, this study is intended to seek the potential application of a turboexpander to lower the cost, such as that can make this project economical. Furthermore, a detailed design and numerical simulation of the turboexpander that will be installed at each wellhead is performed. Because data that available is only in the reservoir condition, this research was conducted with a design study and numerical simulation integrated from subsurface conditions to surface conditions. The results of this study found that the system design with the application of turboexpander wellhead devices in each gas well can reduce the energy requirements of the field system and significantly increase the economical parameters of IRR and NPV in the development of the East Natuna giant gas field. Scenarios using a wellhead turboexpander can reduce processing plant energy consumption by 1.83 GW with a scenario IRR value of 12.68% or increase field IRR by 7.28% compared to scenarios without using a turboexpander which is only 5.4%, with the minimum efficiency of turboexpander that can be applied is equal to 79%. From the results of the turboexpander design and numerical simulation, the most optimum design of the turboexpander design is obtained in the configuration of 26 rotor blades, 25 nozzle blades, and 72? nozzle blade angle, at 25000 rpm rotation. The designed turboexpander can produce 4.65 MW of power from each well with 184.6 MMSCFD gas flowrate, a maximum Mach number of 0.95, at an efficiency of 86.6%